Titanium oxide has found different applications in environmental pollution remediation through its use as a photocatalyst for the purification of air and water. However, despite many advantages of TiO2, its use in unmodified form for photocatalytic reactions is hampered by a number of inherent physicochemical properties. The research in this thesis shows that TiO2 containing either copper (Cu) alone or combined copper-activated carbon (Cu-AC) are active in the simultaneous photocatalytic remediation of nitrate and oxalic acid, while pure titania and titania-activated carbon (TiO2/AC) composites found inactive for the reaction. In the case of photocatalytic removal of phenol, titania-thermally reduced graphene oxide (TiO2-TGO) exhibited superior photocatalytic performance than titania-graphene oxide (TiO2-GO) and pure TiO2.